Heat oven to 200 degrees Celsius. Place butternut and garlic in a roasting pan, season with sea salt and drizzle with 2 tablespoon olive oil and chilli flakes. Roast for 10 minutes. Turn down the oven to 180 degrees Celsius, add the red onion and coat in oil, return to oven to cook for further 20 minutes. Heat a little olive oil in a frying pan and add the halloumi. Cook on both sides for about a minute. Set aside. Mix the chilli, coriander, lime juice and coconut ugar with the remaining olive oil and season with salt and pepper. Toss the arugula together with the butternut, halloumi and red onion (discard the garlic) and drizzle with the dressing. Serve immediately, while warm.